A robotic system using a two-dimensional linear motor is disclosed in U.S. Pat. No. 4,890,241 to Hoffman et al. as the Automatix's products. This motor stator is mounted to the ceiling of a gate-shaped frame. The robots assembling components are installed under a mover, and are moved under the lower surface of the motor stat or. Furthermore, one kind of two-dimensional stepping motor is disclosed in U.S. Pat. No. 4,823,062 to Hoffman et al.
Here, conventional surface-processing machines using lasers are roughly classified into the three kinds shown in FIGS. 9(a), 9(b) and 9(c). That is,
(a) X-axis moving system consists of a conveyor, Y-axis moving system consists of a traverser mounted on a gate, and Z-axis moving system consists of a traverser equipped on said Y-axis traverser.
On Z-axis traverser, a condenser is installed, and the laser-beam is guided to the machining point on a workpiece by a telescopic delivery.
(b) X-Y-Z table system in which a laser is fixed. The workpiece to be machined can be moved in the X-, Y-, and Z-directions.
(c) Turret punch type which is a compromise between the types (a) and (b).
At present, one of the machines (a)-(c) described above are selectively employed according to the size of the workpiece, the required machining accuracy, the kind of the machining operation, and other factors, taking account of the advantages and disadvantages.
Although, relatively, the condenser for focusing a laser beam is essentially lightweight, i.e., 2 to 5 kg, it is necessary to secure the aforementioned machines of high rigidity in order to perform an accurate machining operation. As a result, the machines according to the prior art are considerably large-scale. Recently, higher accuracy is required, and it is necessary to correct the amount of deflection or the mechanical distortion of the coordinate system, depending on the location. This may complicate the control software. In essence, the existing driving system transmits power through complex mechanisms including a servomotor, a ball screw, and various guides. Therefore, it is inevitable that the machine and the driving system are large, complex, and heavy. This has imposed limitations to the response of the servo system. Hence, it has been difficult to improve the existing performance of control further.